Page:Popular Science Monthly Volume 49.djvu/202

on a perfectly faultless basis would, at the same time, rescue our weights and measures of capacity from their present utter confusion.

In presence of the opinion thus expressed and thus supported by evidence, we ought, I think, to hear nothing more about "ignorant prejudice" as the only ground for opposition to the metric system now being urged upon us. But, before proceeding to give adverse reasons of my own, let me quote a further objection—not, it may be, of the gravest kind, but one which must be taken into account. Writing from Washington, Prof. H. A. Hazen, of the United States Weather Bureau, published in Nature of January 2, this year, a letter of which the following extracts convey the essential points:—

The metric system usually carries with it the Centigrade scale on the thermometer, and here the whole English-speaking world should give no uncertain sound. In meteorology it would be difficult to find a worse scale than the Centigrade. The plea that we must have just 100° between the freezing and boiling points does not hold; any convenient number of degrees would do. The Centigrade degree (1°·8 F.) is just twice too large for ordinary studies. The worst difficulty, however, is in the use of the Centigrade scale below freezing. Any one who has had to study figures half of which have minus signs before them knows the amount of labor involved. To average a column of 30 figures half of which are minus takes nearly double time that figures all on one side would take, and the liability to error is more than twice as great. I have found scores of errors in foreign publications where the Centigrade scale was employed, all due to this most inconvenient minus sign. If any one ever gets a "bee in his bonnet" on this subject and desires to make the change on general principles it is very much to be hoped that he will write down a column of 30 figures half below 32° F., then convert them to the Centigrade scale, and try to average them. I am sure no English meteorologist who has ever used the Centigrade scale will ever desire to touch it.

But now, having noted these defects, which may perhaps be considered defects of detail, since they do not touch the fundamental principle of the metric system, I propose, with your permission, to show that its fundamental principle is essentially imperfect and that its faults are great and incurable.

II.

In reply to my inquiries, a French friend, member of the Conseil d'Etat, after giving instances of nonconformity to the metric system, ended by saying:—"En adoptant le système métrique décimal, on n'a pas fait disparaitre tout fait les dénominations anciennes, mais on en a fortement réduit l'emploi." [By adopting the decimal metric system, we have not made the old denominations to disappear entirely, but we have greatly reduced their use.]

It is now more than a century since, in the midst of the French Revolution, the metric system was established. Adoption of it